<?php
/*
 * Shared configuration for maximum base64 payload sizes.
 */

define('BASE64_CHUNK_CONFIG_FILE', __DIR__ . '/config/base64-chunks.php');

function base64_chunk_defaults()
{
    return array(
        'racket_zip_max_base64_kb' => 8192,
        'package_zip_max_base64_kb' => 2048,
    );
}

function load_base64_chunk_config()
{
    $defaults = base64_chunk_defaults();
    $config = is_file(BASE64_CHUNK_CONFIG_FILE)
        ? require BASE64_CHUNK_CONFIG_FILE
        : array();

    if (!is_array($config)) {
        $config = array();
    }

    foreach ($defaults as $key => $default) {
        $value = (int)($config[$key] ?? $default);
        $config[$key] = $value > 0 ? $value : $default;
    }

    return array_intersect_key($config, $defaults);
}

function save_base64_chunk_config($config)
{
    $defaults = base64_chunk_defaults();
    $clean = array();

    foreach ($defaults as $key => $default) {
        $value = (int)($config[$key] ?? $default);

        if ($value < 1) {
            throw new InvalidArgumentException('Base64 chunk size must be at least 1 KiB.');
        }

        $clean[$key] = $value;
    }

    $php = "<?php\n" .
        "/*\n" .
        " * Maximale grootte van base64-payloads, in KiB.\n" .
        " *\n" .
        " * 1 KiB = 1024 bytes. De splitter rondt intern waar nodig naar beneden af\n" .
        " * zodat de binaire chunks netjes naar base64 omgezet kunnen worden.\n" .
        " */\n\n" .
        "return " . var_export($clean, true) . ";\n";

    $tmp = BASE64_CHUNK_CONFIG_FILE . '.tmp';

    if (file_put_contents($tmp, $php, LOCK_EX) === false) {
        throw new RuntimeException('Could not write temporary base64 chunk config.');
    }

    if (!rename($tmp, BASE64_CHUNK_CONFIG_FILE)) {
        @unlink($tmp);
        throw new RuntimeException('Could not replace base64 chunk config.');
    }
}